On 18Dec2013 00:43, Jonathan Ryshpan <jonr...@pacbell.net> wrote: > * Frequently, I start the system, check my email and leave for > breakfast; on these days, I'd like backup to start when I leave; > I would invoke it by a shell script or whatever. > * Other days, I stay on the system for a while; on these days I'd > like cron to start the job whenever its algorithms think best. > * I don't want to leave starting the job completely to a shell > script run from a terminal, because I'd often forget to run it. > > If I can replace cron with at and get the desired result, I'll be happy.
Cron's algorithms are pretty simple; the do things when you tell them to:-( If it were me I'd be doing this as follows: I have a "flag" command: https://bitbucket.org/cameron_simpson/css/src/tip/bin/flag I'd have a cron job for midnight that sets "BACKUP_DUE" to 1: flag BACKUP_DUE 1 I'd have a core script that runs the backup with not checks of controls. I presume you have such. I'd have a wrapper script that takes a lock, checks BACKUP_DUE. If false, do nothing, maybe report "backup not due". If true, set it to false and dispatch the core script. Release lock. Untested hack: if mkdir /tmp/backup_lock then if flag BACKUP_DUE then flag BACKUP_DUE 0 core_backup_script 2>&1 | mail the-sysadmin & fi rmdir /tmp/backup_lock fi Have a cron job that fires at 10am or whenever that is fallback for your manual backup dispatch. Just an idea, -- Cameron Simpson <c...@zip.com.au> I made this letter longer than usual because I lack the time to make it shorter. - Pascal -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
